Sources allegedly told TMZ that the letter says the boys often lapse into a "zombie-like state" and become out of control and violent toward adults, children, and pets. According to the letter, Richards said she observed the twins strangling her dogs as well as her three daughters. As with the dogs, Bob and Max kicked her children in the head. The twins also spit, scratch, bite, slap and punch her children, she said, according to TMZ.

The violence is not limited to the home. It also occurs at school, TMZ reports. Richards claims that Bob in particular has slapped and punched teachers.

Mueller, who is currently working on her drug addiction, has blocked efforts to get the boys counseling, Richards said in the letter, sources told TMZ. The twins’ behavior is reportedly worst after returning from spending time with their mother at home.

Online commenters of the New York Daily News article expressed concern for the twins.

“Think of the prenatal drugs these kids ingested — thanks to their mom,” wrote one poster. “Combine this with her psychotic DNA = lifetime of problems. Why on earth did she & Charlie have these kids anyway? He already had several.”